Update READMEs with up-to-date Meilisearch usage instructions

[curquiza]

👉 Update in all integration READMEs

• Replace the inside of the Run Meilisearch section with

⚡️ **Launch, scale, and streamline in minutes with Meilisearch Cloud**—no maintenance, no commitment, cancel anytime. [Try it free now](https://cloud.meilisearch.com/login?utm_campaign=oss&utm_source=github&utm_medium=meilisearch-XXX).

🪨  Prefer to self-host? [Download and deploy](https://www.meilisearch.com/docs/learn/self_hosted/getting_started_with_self_hosted_meilisearch?utm_campaign=oss&utm_source=github&utm_medium=meilisearch-XXX) our fast, open-source search engine on your own infrastructure.

⚠️ Replace meilisearch-XXX with the appropriate integration name

• Remove the section about Cloud at top of README